math/w_exp2f.c

   1 /*
   2  * wrapper exp2f(x)
   3  */
   4
   5 #include <float.h>
   6 #include <math.h>
   7 #include <math_private.h>
   8
   9 static const float o_threshold = (float) FLT_MAX_EXP;
  10 static const float u_threshold = (float) (FLT_MIN_EXP - FLT_MANT_DIG - 1);
  11
  12 float
  13 __exp2f (float x)
  14 {
  15   if (__builtin_expect (x <= u_threshold || x > o_threshold, 0)
  16       && _LIB_VERSION != _IEEE_ && __finitef (x))
  17     /* exp2 overflow: 144, exp2 underflow: 145 */
  18     return __kernel_standard_f (x, x, 144 + (x <= o_threshold));
  19
  20   return __ieee754_exp2f (x);
  21 }
  22 weak_alias (__exp2f, exp2f)